问题如下图：
选项：
A. 
B. 
C. 
D. 
解释：
想问下使用历史数据这个选项错误的原因，历史数据不是基于真实的吗，这也算是个有点吧？还是说c选项包括了优点和缺点所以不选？
历史数据不能用是不是历史不能预测未来这意思？
availability of tuse of historict little or no relianon covarianmatrices The use of historicta in non-parametric analysis is a saantage, not aantage. If the estimation periowquiet (volatile) then the estimaterisk measures munrstate (overstate) the current risk level. Generally, the largest Vcannot exceethe largest loss in the historicperio On the other han the remaining choices are all consireaantages of non-parametric metho. For instance, the non-parametric nature of the analysis caccommote skewetta points are realy available, anthere is no requirement for estimates or covarianmatrices. a为什么不选?hs难道反映了偏度吗
历史数据是缺陷?应该是算优点啊。。
availability of tuse of historict little or no relianon covarianmatrices The use of historicta in non-parametric analysis is a saantage, not aantage. If the estimation periowquiet (volatile) then the estimaterisk measures munrstate (overstate) the current risk level. Generally, the largest Vcannot exceethe largest loss in the historicperio On the other han the remaining choices are all consireaantages of non-parametric metho. For instance, the non-parametric nature of the analysis caccommote skewetta points are realy available, anthere is no requirement for estimates or covarianmatrices. 请问B如何理解呢？
availability of tuse of historict little or no relianon covarianmatrices The use of historicta in non-parametric analysis is a saantage, not aantage. If the estimation periowquiet (volatile) then the estimaterisk measures munrstate (overstate) the current risk level. Generally, the largest Vcannot exceethe largest loss in the historicperio On the other han the remaining choices are all consireaantages of non-parametric metho. For instance, the non-parametric nature of the analysis caccommote skewetta points are realy available, anthere is no requirement for estimates or covarianmatrices. 该怎么理解啊？
